Flushing devices and drain fittings of this type have been known, and they make it possible to save considerable amounts of flushing water. Therefore, there is great public interest in the widespread use of such flushing devices. The flushing devices which have become known to date and have been used in practice usually have a very complicated design and consist of many individual parts.
For example, a flushing devices, in which the valve body is connected to a weight body in the resting position, is disclosed in EP-A-0 448 092. The weight body is separated from the valve body in the case of complete flushing. In contrast, the weight body is raised with the valve body in the case of partial flushing.
German Utility Patent No. DE-U-92 15 972 discloses drain fittings, which also make possible a complete or partial flushing. This operates with an auxiliary valve and an additional auxiliary valve as well as with an overflow chamber, and it likewise has a very complicated design.
Finally, DE-A-36 18 671 discloses a flushing means in a toilet flush tank, in which a weight supported on the float housing is carried during the raising of the valve body by means of a control member for triggering a partial flushing.